- Previously treated patients; retroperitoneal fibrosis secondary to drugs(e.g. methysergide, methyldopa, pergolide, ergot alkaloids), infections (e.g. tuberculosis), cancer (e.g. lymphoma, sarcoma), radiotherapy, trauma, major surgery, systemic connective tissue or vasculitis disease (e.g. SLE, panarteritis nodosa); pregnancy; active infections or tumours; known hypersensitivity to prednisone or tamoxifen; uncontrolled diabetes.